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fakeflyer737

HUD LNAV Track

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Guys, I'm having a problem accuraely flying in LNAV (manually) with the HUD, is there something on the HUD other then the "bug" to tell me if Im left or right of track. It seems I fly alot more accurately without the HUD; despite the fact that the HUD is 6x more sensitive then the DU's ( I think). I just don't know when to start or finish a turn and how to really get perfectly on Track with the HUD. Any ideas? Maybe one of you can do a tutorial with youtube about the HUD. It seems to an extremely advanced piece of NG gear; yet it is the least understood....by me anyway.Cheers

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HUD seems to suffer from lag during lnav flight. FD on PFD seems far more accurate and easier to use to follow lnav track. This been mentioned before but not really commented on by pmdg.

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No inaccuracy that I'm aware of. The CDI on the HGS does not show the LNAV deviation according to our documentation from Boeing, only the VOR course.

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No inaccuracy that I'm aware of. The CDI on the HGS does not show the LNAV deviation according to our documentation from Boeing, only the VOR course.
So how do a hand fly LNAV with the HUD?

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So how do a hand fly LNAV with the HUD?
Just keep the flight director circle inside your flight path symbol and you should be spot on. Use the primary mode, which is basically the PFD represented on the HUD.I've never noticed any lag. The Flight Path symbol I'm sure has some minute lag, like any performance instrument, but it should not keep you from flying correctly.

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I've not really tried it since the latest sp, but always found before that keeping the circle in the circle didn't really keep you on the lnav track. It doesn't seem to preempt the turns, like the FD does. It almost seems more like it follows you rather than you following it as it were.If I hand fly watching the FD I can keep it on track, using th HUD I'll end up yo yoing through the lnav track. I'll give it another try hand flying the Sid later with the latest sp.

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I've not really tried it since the latest sp, but always found before that keeping the circle in the circle didn't really keep you on the lnav track. It doesn't seem to preempt the turns, like the FD does. It almost seems more like it follows you rather than you following it as it were.If I hand fly watching the FD I can keep it on track, using th HUD I'll end up yo yoing through the lnav track. I'll give it another try hand flying the Sid later with the latest sp.
Precisely, that's what I'm saying, there seems to be no Lead in or Lead out of the turns and its very difficult to fly RNAV SID's with a lot of points near each other; ie Boston Reeves1 SID off of 04R. Try that SID with HUD and fly it in manual its hard as all hell without looking at the Nav Display.

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Precisely, that's what I'm saying, there seems to be no Lead in or Lead out of the turns and its very difficult to fly RNAV SID's with a lot of points near each other; ie Boston Reeves1 SID off of 04R. Try that SID with HUD and fly it in manual its hard as all hell without looking at the Nav Display.
Why not look at the ND? You can use it as a reference for what's to come. I love to fly SID/STAR with AP off with the HUD in LNAV/VNAV. Haven't found myself much off the track so far. Maybe it improves with higher refreshrates for you. Set them up via the option pages in your fmc...

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I have to think it's pretty uncommon to have the HGS down outside of low-vis takeoffs and approaches anyway...

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This aircraft is a pure joy to fly by hand...how ever you do it. I never tried using the HUD for in flight navigation before. I will give that a try.

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Depends, Ryan, I guess... Some airline reportedly have a SOP to use HUD ALL the time. I personally use it for every TO and landing, if installed, although I stow it for climb, cruise and descent.

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Does anyone with first hand knowledge know for a fact if carriers such as Delta or Southwest fly with the HUD down all of the time? I generally always have it down, as I have seen on real life photos, even during cruise.

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Depends, Ryan, I guess... Some airline reportedly have a SOP to use HUD ALL the time. I personally use it for every TO and landing, if installed, although I stow it for climb, cruise and descent.
You are right. AZUL in Brazil SOP for the Embraer eJets is to have it down at all times.

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I have this problem too, most problem is it when there is hard turns in the SID wich would often result in missed waypoints if only flying whith the HGS. But after reading the FCTM I found out that the HGS doesn't work well with hard turns and a conventional head down flying is preferd after the take off. So I always fly head down after take off and with the PFD/NG you can't fail a SID departure.

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Yep, likewise, love flying SIDS manually, but using HUD doesn't make it very easy. If I follow the FD bars on the PFD instead I'm spot on most if the time, just be niceto do it heads up instead and use the HUD which is what I thought the whole point of it was! So is it a case of there being an issue with the HUD in the ngx or is it like this in real life where it's slow and unable to predict a turn?

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The main reasons to use HUD are elsewhere, not in flying SIDs. I believe it could be made so it worked same as the flight director, but by that you kind of lose a point of HUD, which is to show accurate FPV relative to the actual aircraft surroundings.The fact that HUD uses the FPV as the tracking point rather than attitude indication is for example very handy in difficult visual approaches, where pretty much all you need to do is point the FPV at the runway, or the landmark you need to navigate to.By design, FPV does not work well in tighter turns though...To clarify, the parts when you need to look out, is on actual take-off until shortly after rotation (so that you keep it on the runway) and then landing. After a take-off, especially low-vis take-off, there is no need to look out at all, since you will not see anything but grayness/darkness anyway.

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